CA2118320A1 - Production of reproductive hormones - Google Patents

Abstract

Improved methods for recombinant production of human reproductive hormones are disclosed. These methods involve the use of animal-derived cells that contain regulated secretory granules as host cells for expression systems capable of expressing DNA encoding human reproductive hormones or their .beta. subunits.

Description

- WO93/21~47 2 1 1 8 3 2 0 PCT/US93/~051 IMPROVED PRODUCTION OF REPRODUCTTVE HORMONES

Thi invention was made with gover~ment ~upport under NIH Contract No. N01-HD-9-2922 awarded by ~he National In~titutes of Health. The U.S. ~overnment has S cer~ain ri~ht~ in:this invention.

~: : Te~-Jhci~ i91~
The invention relates to methods for rec~mbinant production of human reproductive hormone~
with glycosylation patterns more clo~ely reIated to native patterns than generally obtainable in transformed cells.~ In part~icular, it concerns production of :recom~i~ant hormone ~nder conditions which result in e:fficient production and; ecretion and which regulate the gly~osyla~ion~::pattern of the protein.

Human reproductive;function is controlled in part:~y~:f~amily of heterodimeric human:glycoprotein.
ho~mone~whi~h:~haYe a~co ~ o~ a:~æubunit, but differ in their~hormone-~pecific ~ subunit~.:: The family i:ncludes 20~ ollicle~-st~imulating:~hormone (FSH3, luteinizing hormone (LH)~ thyrotr~pin~o~thyroid-stimulati~g ho~mone (TSH), and~human chorionic gonadotropin (CG)~. ~In all cases, the subunit i~ a 92 amino acid glycoprotein with two canonical glycosylation sites,at,the asparagines located :25 ~::at~po~ition~ 2~and~78. The ~ subunit~ are also glycopr~teins~: in addition:to the~N-linked glyco~ylation exhibited by:the:~;chains:of all four~:hormones, human CG
contain~ four~mucin-~like O-linked~oligosaccharide`s attached to a car~oxy-te~minal extension unique ~o this ;: 30 ~ hormone~ The rele~ance of the O-linked;glycosylation is :: not, apparently, related to the secretio~ and as~embly of ~: i : :

W093/~19~7 ~ 1 1 8 ~ 2 0 P~T~S93/o40~1 ``

the ho~mone ~M~tzuk, M.M. et al. Proc Natl Acad Sci USA
(1987~ ~4:6354-~35~).
Genomic and cDNA clones have been prepared : corresponding to the human ~ chain tBoothby, M. et al. J
~5~ ~m (1981~ 256:5121-5127; Fidde~, J.C. e~ al. Mol A~p Genet (1981) 1:3-18). The cDNA and/or genomic ~; ~equences of the ~ subunit~ have also been prepared. For CG, the ~-encoding DN~ i8 described by Fiddeg, J.C. et al:. ature (1980) 286:684-687 and by Policastro, P. et al. J Biol Chem (1983) 258:11492--11499. For luteinizing hormone, hereto, uch description is by Boorstein, W.R.
et al. Nature (1982~ 30Q:419-422; and-for TSH by Ha~a~hizaki, Y. ~t al. FEBS ~ett ~1985) 188:394-400 and y Whitfield, G.K. et al. in "Frontiers in Thyroidology", 15~ 9a6)~ Medeiro~-Nato, G. et al. (eds) page~ 173-176, Ple~um Press, NY. These DNA segment~ ha~e been expre~sed rec~m~inantly, and biologically active material has been :pr~duc~d.: : ~ :
The genomic sequence~encoding FSH~ chain was 20:~ u~ed to construct a~:~recombinant:e~pre~sion ~ec~or ~A~
c~:aini~g the complete ~:chain coding 3equence as escribed in~P~T application W0 ~6/04589, publi hed 14 Augu~t l9~. I~ addition genomic clones for human FSH-~have~been prepared~by others (Wàtkins, P.C. et al. D~
2s:~ 987)~6:2os~-2l2;:Jameso~ J.L- et a~ J y~LL~L
(19883 c806-8~15; Jame80n, 3.~. et al. J Clin End~orinol :M~ab (19~6):64::319-327;~Glaser, T. et alO Nature (1986) 882-887):. PCT:~applira~ion~WO 90/09800 describes the - expresRion of human~FSH in Chinese ham$ter o~ary cells.
30~ ~The bovine ~-FSH gene ha~also been~o~tained as disclosed in Maurer,:R.A. et al. DNA (1986) 5:363 369; Kim, K.E. et a~. DNA (1988j 7:227-333. ~ :
~: The above-refarenc d PCT application W0 ~ ~ 90/09800 discloqes a number of e~pr~ssion systems for : :: :

WO93/21947 2 1 1 ~ 3 2 0 PC~ 93/04~S1 human reproductive hormones including their a subunits and ~ subunits~ In addition, this application describes ~: certain m~teins of the ~ and ~ subunit that are useful by virtue of their alteration of ~ecretion characteristics or ~lycosylation patterns~ However, the expression systems de~cribed specifically in the above-referenced PCT applioation are limited to murine cell9 and Chine~e hamster ovary cells. The pxesent application describes the uEe of expre sion systems of the type disclo~ed in the abo~e-referenced application in celIs containing e::retory granules, e~pecially pituitary-derived cells.
: ~ : Thi : results in mature forms of the ~ subunits or :heretodlmers glycosylated in a manner analogous to their native ~orms, as:~well as an enhanced capability of the :15~ cell~:to~ecrete;the hormone.

Di closure of~the InventiQn :The invent:ion prQ~ides:cultures which are capable of ~e~reting forms of human gonadotropins, luding~their~:indiYidual ~ subunit , and including .~-~
~muteins of~ehe~hormone and subunit~ which havegl ~ osylation patter~s;similar to the~natively produced materi~ls and~which~are ~apable of~beln~ ~ecxeted into :t~e~medium.~ Secretion ints the:medium~greatly ea es the p~oce~ :o~ purification of the;~ormo~e:~pro:duced and the glyco ylation~mimicking that of the nati~e ~ubstance permi~s ~e~ter predictability of behavior i~ vivo in ~iew ; of the accumulation of data with regard to the nati~e materials.
; :: : Thus, in one:aspect, the invention is directed-to a me:~hsd to produce human~reproductive hormones na~lotropins~ or their ~ subu~its~xecombinantly, which method comprises culturing cells derived from animal tissue which:cells contain secretory granules, that ha~e :: : :
~: :
:~

W~93/21947 2118 3 ~ O PC~/USg3/~051 been transformed with an expression ~ector capable of expressing a DNA encoding said human reproductive hormone or ~ ~ubunit thereof under conditions where aid expression is effected and xeco~ering the hoxmone or : 5 subunit ~rom the ~upernatant of the culture. In another a~pect, the invent~ion is directed to the cul~ures of `these transformed cells useful in the method of the inventio~. :

Brief Desc~1E~isa~ _f the Drawinqs ~: 10 ~igure 1 ~hows a diagram of the con truction of : the human ~ subuni~ minigene, and vectors for it~
:: ` ;
xpre~io~
Figure 2 ~hows a diagram of the construction of the extended form of FSH ~ subunit.
15~ igure 3 ~hows a photocopy of a gel run on 35~5-cystei~e labele~ hH-~ subunit and 35S04 labeled or ;S-cys~eine:labeled LH dimer recombinant super~atan s.
Flgure 4, panel A is a photocopy of a gel 1 on lys~ate~ and mRdia of:~su1fate labeled~hH-e ~ ressing cel~
O~ in~the~pre e~ce and~absence of ~ecxetagogue; panel B
ohow the results of treatment with Endo~P.

Modes~of:~:carrvl~3L~~ Y5~S~.~
: As~used~erein, human ~ subunit, and human FSH, ~H, TSH, an~ ~G-~ subunits as well aæ the heterodimeric ~' 25 forms ha~e in ge~eral their conventional defi~itions and referred to ~he proteins~having:the amino acid equences known in the~art per~se,: or allelic variant~ thereof, deliberately constructed muteîns the}eof maintaining the activi~y of the nati~e:protein:~regardless of the g~lyco~ylation~pa~te~n exhibited, or:~mut~ant ~orms thereof having at lea~t 90~` homology with the native forms.
'Huma~ reproductive hormonea:" or gonadotropinsll and :
~ ~ .

W093~ 47 2 1 1 8 3 2 0 PCT/~S93/W~51 S-subunits thereo refer~ to the~e four heterodimers (or their muteins) and subunits thereof.
: "Native" forms of these hormone~ or ~ubunits are those which have the amino acid sequences i~olated from human ti~sue, and have these known sequences per ~e, or their allelic ~ariants.
"Mutein" forms of these proteins are tho~e which have deliberate alterations in amino acid sequence produced h~, for example, site-~pecific mutagenesis or by other recombinant manipulations, or which are pr~pared ~ynthetically. The e alterations re~ult in amino acid sequences wherei~ the biological activity of the subunit is retai~ed a~d/or wherein the subunit has at least 90 homolo~y with the nati~e fo~m.
~ For~example~ a preferred mutein of the subuni~for use in:a~tagoni ts of the varlouR
heterodimer :~has~ alterations in the amino acid~ of po~itions:88-92:.: ~ ;
A part~i~ularly preferred~mutein of FSH-~ or :20 ~ or ex~m~le,~is:~an "extended" FS~-~ or~H-~ whe~in th~ amin~acid~se~ue~ce compris~in~the carboxy-terminal peptide~(CTP)~:of hCG iB fused to~the~car~oxy terminu of PS~-~ or~ :. A~us~d~herein, "CTP"~refers to the "extra" equence ;at~the~C-termi~us::of:the CG-~ peptide a~
2s~ compar~d~to the other~related hormones.~ The length of the effecti~e CTP:a ~:~ompared to the other ~ subunits may vary slightly'but it extends from roughly amino a~id ; 112-118 of CG~t~residue~145 at;the~C-terminus. The preci e length::of:~TP~in the:constructs here`in will be 30 ~clear from the content. : ~ :
In~the~usi~ns~describe:d~herein, native CTP can : be u3ed or a~"varian~":thereof.~ By i'variant" is meant a con~ervative analog of the peptide~residu~s from ~bout 2-l18 to: 145, i.e~. thi~ sequence wherein about 1-5 :: : : ~ : :
:
., ,, . , . ., =..

W~ g~/21947 2 1 1 8 3 2 0 PCI/US93/04~5~

amino acid~ of the sequence are altered without æubstantial change in propertie~. Often this variation results ~imply from muta'cion to obtain appropriate restriction sites.
Although it i~ recognized that glycosylation pattern ha~ a prof ound inf luence on activity both qualitatively and quantitatively, for convenience the :: : terms FSH, ~I, TSH, and CG ,B subunits refers to the . amino : : acid sequence characteristic of the peptides, as does : 10 ~ubunit". When only the ~ chain--is re~erred to, the terms will be, for example, FSH-~; whèn the heterodimer is referred to, the simple term "FSH" wi11 be u~ed. It will be clear from the con'cext in what manner the glyco ylation patterIl is affected by, for example, s ~ 5~ recombinant expxession ho t or alteration in the glycosylati~ n ites. Forrns of the glycoprotein with ;: Epecified glycosylation patterns will be so ~oted .
As :used herein, the a subunit "minigl~ne" refers to ~ithe géne constru~tion disclosed ~ in PCT applicatiorl WO
o ~ 90/0980:0 in the description of the coxl~;truction of ,.~, 12/CGa or p~l2/cY. ~This "minigene" i5 characterized by rete~tion only ~of 'one iiltron sequence such as that between exon III and~ exon IV, all other introns ha~ring been~;deleted:.~In the particular construction described, t~e~N-terminal:co~ing sequenc~s which are derived from ~: exon II and a~portion of exon III are ~pplied from cDNA
: a~d arè ligated directly through an ~baI re triction site : into the coding se~uence ~f exon III 80 that the i~tron~
between exons I and II and between exons II and III are absent. Howe~er, the intron between:exons III and IV as well as the signals 3~ of the coding ~equence are :: retained. The resulting minigene can con~eniently be ~:: inserted as a BamHI/BglII segment. Other means for ~ construction of a comparable minigene are, of cour~e, :: :

wo 93/2lgq7 2 i 1 8 3 2 0 P~T/U~93/OqOSl possible and the definition is not restricted to the parti~ular construction wherein the coding se ~ ences are ligated through an XbaI site. However, this is a con~enient means for the construction of the gene, and S there i~ no particular advantage to other approaches, such as synthetic or partially synthetic preparation of the ge~e. The definition includes those coding se~uences for the ~ subunit which retain one intron such as t~at between exons III and IV but no other introns.
~: 10 A~"tran~formed" recombinant host cell, i.e., a cell ~transformed~ with the recombinant expression ~ystem~ of:the inve~tion, refers to a host cell which has bee~ alt~red to contain this expre~ ion sy~t~m by any conveni~nt manner of introducing it, including ~:~:; 15 tra~sfection, viral infection, and 80 forth.
: "Tra~sfonmed" refer~ to cell~ co~taining this expression system wh~ther the ~ystem is integrated into the chro~osome or is~extrachromosomal. The "transform d~
cells:may either be stab~e with re~pect to inc~usion of 20:~ ~the expression system or not. In~short, recombînant ~st cells~"transformed" w~ h the expre i~n ~y~tem-of the : invention ref rs:t~ cells which include thi~ expres~ion ystem as a; re~ult~ of their manipulation to include it, when they na~i~el~:do not, regardle~s of the ma~ner of 25 ~: ef~ect~ing ~his inco~poration.
Expression ~y~tem" re~er to a DNA sequence which i~cludes a coding sequence to be expre~ed and : tho~e accompanying control D~A sequences nece~ary ko effect the expre~sion of the coding ~e~ue~ce. Typically, 30~ these control inc1ude a promoter, termination regulating equ~nce~, and, in ~ome cases,~an ~perator or other mechani m to regulate expression. Th co~trol sequences are tho~e which are designed to be functional in a particular target recombinant host cell and ~herefore the WO93/21947 . . PCT/US93/04nSI

host cell must be chosen ~o ~s to be compatible with the control sequences in the constructed expression system.
As used herein "cells~ 'cell cultures", and : "cell lin~" are used interchangeably without particular attention to nuances of meaning. Where the di~tinction etween them is important, it will ~e clear from the context. Where any can be meant, all are intended to be include~.
Certain cells are known to contain dense-core ~secretory gr~ules and to secrete proteins through a regulated pathway, which can be stimulated by certain ~ubstances, for example, forskolin. These cells or cell Iine , deri~èd from appropriate animal ti~ues, are the ho~t celIs of the invention. Included among cuch cells :l5~ are cells of~the secretory component~ of ~he hormo~e y tem~uch;as~:the:pituitary, ~ i let cells, and cells of the~adre~al co~tex:.:~ Particularly preferred in the method of; the invention are pituitary-derived cell~.
o~ tent~with the foregoing paragraph, "cell~
2:0~ ;deri~ed rom:pituitary" refers:the cellR or cell lines ;which~are cultured~fr~m pituitary tissue:derived from ani~al~ pe:cies,; in particular;mammalian specie~, and more paxticulàrly,:~hu~ar or:murinç;pituitaries. Illustrated herein i~the G~3 murine~cell~line described by Tasjian, 2~5~ :J.,~ (197:9):~ 5~7.: However, other lines derived:from~the:pituitary~are~al~o ~nown and obtainable rom p ~ lic depo~itories. In addition, cells deri~ed directly from~pituitaries:may~be~:~u~ed. ~ ~
Cell~s containing ~ecret:ory::granules provide an ;30~ environment:more like that :o~ ~pituit~ry cells as opposed to CHO cell~. This re~ultæ in glyco~ylation patterns : : more like the nati~e orms~:and enhances ~ecretion efficiency of proteins~to be secreted.~ ~Production of the : gonadotropin~ in such cells,~containing dense-core ::: :

~-.. W0~3/~1~47 ~ 3~ o P~T/U~93/040~1 secretory granules capab~e o secreting proteins through a regulated pathway thus results in the production of secreted forms of these materials with glycosylation patterns similar to those found in the native hormones or subunits. In particular, these forms of the hormones or subunits ~u~h a5 LH which retain labeled sulfur ~upplied in the form of sulfate do so when produced in these cells ~: indicating that ~ulfated glycosylation units are presen~
in the~e forms. ~abeled SO~ 2 i~ not incorporated into : : 10~ ~H produced in CHO cel}s or murine Cl27 cells.
~: While FSH is normally sialylated, the ~ subunit of ~H is normally sulfated. Sialylation of N-linked : : o1igosaccharide~ has long been recognized to pxotect :circulating gonadotropin from clearance by hepatic 15 ~ asialoglycoprotein receptor In contra~t, the pre~ence , ~ ~
` ~:: : ~ o~ulfate on ~H lead to a rapid;clearance of the h~ ormone; ul~ated b~vine LH h~s a 4-5 fold faster ~et~bolic clearance compared to the corre~ponding ialy1at~d~re~ombinant bovine L~I. Sulfated LH is removed 2;0 ~ om~ci~culation upon binding to a ~pecific receptor p~
;the~surface:o~liver epithelial cells which re~ognizes a specific ~ulfa~ed trisacchari~e in ~he~N-linked glycosylation.~;~ De~ulfated ~H~behaves simi~arly to ;:sul~ated~hX~in~recept~r binding:and ignal transd~ction ; 25~ in~:MA-~lO cel~ls,~but~hi~h in~ vivv do9es are requixed to ti~ulate o~ulation,~pre~umably be au e ~he circulatory half life is altered by sulfation. It is believed that clinical u~e of ~R:in human~or animal reproduction wilI
requlre the hormone~in~sulfated form.
, 3:0~ ExPression Vectors ~ ~
:~ ~To co~struct ~uitable:expression vectors for , use in the ~ecretory cells of the invention, a convPnie~t co~struct,~ iIlustrated for the ~ subunit minigene i5 ~::
:

WO93/~1~47 21 1 832 0 P~/U~93/~051 :~

reproduced from the above-referenced PCT application as Figure 1. As shown in this figure, and as more fully explained in the above-referenced app~ica~ion, the se~uence encoding the ~ sllbunit is prepared as a minigene wherein the portions of the peptide encoded by exons II-III are fused but separated from exon IV. Thi~ construct : is ligated into the host vector pM2 under the control of the long terminal repeat ~hown in Figure 1 to obtain : pM2/CG~ or to obtain pM~a which contains an additional ~0 insertion site for another coding D~A. As further shown in Figure l, the BamHI site contained in the ho~t vector pM2 can be u ed to accommodate the ~ subunits of the human r productive proteins for expre~sion of the~e subunit per~ se, a well a~ providing a separate ; 15 ~expr~ssio~ vector for concomitant production of the a and subunit by rells tran~fo ~ ed by both vectors.
Thus, the:~ sub~nits per se may be produced by ligating the coding DNA ~into pM2 a~ ~hown, or the heterodimer may be produced by cotra~sfo ~ ation of pM2 :~aontainîng ~A;encoding ~ ~ubu~it with pM2/CG~
Production of ~he;heterodimer i~ preferred. The heterodimer may:also~be~produced from the;single vector wherein the ~ in ert i liyated into the Bam~I site of pM2/a~créated~by ligation of EcoRI-digested pM2 with 25~ ~co~ dige~ted modified pM /CG~ -:~: The ~oregoing construc~ions are, of cour e, ' ~ merely illu~trative of expression vectors or ~ystems~
: : which an be constructed for the prod~ctio~ of ~ subunits or the correspondi~g:heterodimeric hormones. Alternate ;: : 30 :control ~equences incIuding, for exa~ple, different : ~ promoters, can be ligated to the coding seque~ce of human ubunit~ or the a minigene to effect expression. A
~:~ : ~ariety of control sequences is known in the art, and methods to ligate the ~ subunits or ~ minigene coding ~ :

W093/21947 2118 3 ~ ~ PCTlUS93/~51 sequence (or other ~-encoding construct) are of course also available~ Suitable mammalian promoters include the early and late promoter~ from SV40, or other viral : promoters such as those derived from polyoma, adenovirus : 5 2, bo~ine papilloma virus or avian sarcoma viruses.
: ; : Suitable viral and mammalian enhancers can also be used.
~ As ~et forth in the Background section above, ;~ the recovery of the genes for the various ~uman :
reproducti~e hormones, including their ~ subunits, has : 10 already been described. The genes can be recovered from native ~ource~ as described in the art, or the genes can be entirely or partially synthesized u~ing ætandard solid phase oligon~cleotide ~yntheæis techniques as described, :;for example, ~y Nambiar, K.P. et al. Science (~984) 5;~2 1299 or by Jaye, E. et al. J Biol Chem (19843 259::6311. The ~echniques are now commercially ;ava~ilable. It~i~ evident, of cour~e, that not only th~
specific native nucleotide ~equence~ can be employed, but al~o nu:~eotide equences:employing codons which are o~ degenerate~with thes~e~,~ as~well:~a~s~allelic~forms. .~-~: AB f~rther~de~cribed~in the aboYe-referenced PCT~applicatio~n,:muteins of the:variou~ hormone~ can be o~tained~:which:have~agoni~t or antagoni~t activity.
These~mutein-encoding~genes~may~be inserted into the 25 :~ rele~ant ho t:vectors in a manner~:similar to that de~cribed for~the nati~e for~s. Of parti~ular intereæt : are mutein wherei~ the:~ subunits of LH, TSH or FSH are : extended b~ the carboxy:terminal peptide native to :: : chorionic gonadotropin.: One ~uch ~on~truct is 30~ lu~trated in Figure 2 for human~F5H. In addition, more than one of t~e ~TP~uni~s may be used to extend the : chains.

: , WO93t21947 ~ 3 ~ O PCT/U~g3/~051 In general, the selected expression v~ctor or vector~ is transfected or otherwise transformed into the host cells of the in~ention using procedures similar to ~:S those u~ed generally ~or mammalian cells. The techniques ~: ~for tran~formation are ~ubstantially those applied with re~pect to Chine~e hamster o~ary cells, and ~y~tems for marker~ for selection of succe~ful transformants are : ~- a1so ub~tantially~identical. Cell culture conditions for the ~ransfonmed cells ma~ be---modified as is generally under tood to accommodate ~he particular need~ of the selected ho~t cell line which will contain reyulated secretory g~anuleæ; however, culture conditions are ` 8ub8ta~tially similar to tho e u ed for ~HO cells a 15~ well. ~
In an illustrative approach to transfection and cultu~e, the:~subunit-encoding yene i9 inserted into pM2 an~then transfected alone or along with~pM3/CG~ into the ce~ ;appropriate for the method of the:invention which `O~ con~ain regulated ecretory granu1es or into Chinese ~-~iham~ter~o~ary:cells as~a contr~l,~a~ described by Matzuk, M.M.~ et~al., ~b=~ g~bS~ L (;1987) 8~:6354-6358;
Matzuk~ M.M.~ e~al., ~ 5~LL~al:(19883 106:lO49-1059.
Succe~ful transformant :are ~elected in 0.25 ug/ml G4l8, 25:~ and~e~pre sion~may~be~detected ~y~immunoprec:ipitation of : metabolically labele~ cells to elect:monomer- and dimer-secreting cell lineB.
- Both~stably tran~fectQd~hosts ~ontaining resulated secretory granule and:~tably tran~fected ~HO
: 30~ cell~;lines are maintained in "medium-~l" (Ham'~ FlO medium æupplemente~ with 1~5% horse serum`and 2~5~ fetal calf :
erum, penici1lln (100 U/ml), streptomycin (lO0 ~g/ml), :glutamine (2 mM) and 0.125 mg/ml G~l~ in a humidified 5 ,~
:C2 incubator.

~ .

.. WO93/21947 2 1 18~ ~ P~T~US93/0~51 Labelinq Both cells of the invention and C~0 cells are plated at 300,000-350,000 cells per well into 12-well di~hes in 1 ml of F-10 medium containing 15~ horse serum ~ ~ S and 2.5~ fetal calf serum and pr~plated 3-4 days. For : : : continuou~ labeling, cells are washed twice with ; cysteine-frèe "medium-2" (medium~1 supplemented with 5~
dialyze~ calf ~erum) and labeled for 6 hours in 1 ml of cysteine-free~medium 2 containing 20 uCijml la~eled 0 ~ cyseeine. ~For pulse cha~e experimentæ, the cells are washed twice and preincubated for 1.5 hours in cy~teine-~ree medi~m-2,~fo~1Owed by a 20 minute labeling in cy teine-fre@~medium-2 contai~ing 100 uCi/ml labeled :cy~teine,~ then washed twice with medium 2:containing 1 mM
5~ unlabeled~cyst:eine and incubated in the unlabeled medium.
a~elin~ ~periment~ using incorporation o 35S:-labeled sulfate~are~aonducted similarly.
In~more detail the medium`and cell ly~ate are prepare~, immunopre~ipitated, and:treated~as described by 2~ ~rle~6,~ c.~ et al. ~ J e1l ~ioI~ 87): 104:1173~
and~ he~Matzuk~P~a~ paper cited~above. Anti~era agalns~ G~ ~H~ :FSH-~ and T9H~ and the ~ ~u~unit are preparèd~by~tandard:methodsi:~antisera~generated against CG-~cro~s~-~reaetæ ~ully~with ~ a~d~can be u~ed to 25;~ ;detect LH-~as well.~ ~For ~haracterization of the : immun~precipi~ate ~n SDS ~els,~ SDS~polyacrylamide gel are soaked for~10 minutes in l M~sodium ~licylate, d~ied~ and;autoradiographed~with preflash film,: ~nd scanned, i~: desired, with:an LKB~Ultra~can X~ lasex:
3~0:: ~den~itometex.~

: As~a~cor.trol, the results~:of production of : human FSH;in:CHQ cells is asseæsed by l~elin~ with ~: ' :
::

WO93/21947 2 i 1 8 3 2 0 PCT/US93/~1 cy teine. The expres~ion systems described above for human FSH-~ inserted into pM2 for expression of F5H-~alone or into pM2/~ for expre~sion in tandem with the ~
subunit were transfected into CHO cells and stable clones shown to e~pregs the ~ subunit or dimer were continuously labeled with 35S-cy~teine for 6 hr. Yields of secreted FSH of approximately 1 mg/106 cells/24 hr cultured in 1 L
of medium were obtained.
: The proteins secreted into the media and from cell ly~ates were immunoprecipitated with appropriate anti~era and resolved on SDS-PAGE. The results obtained : com~are the behavior o~ similar transformants expressin~
the gene for human C~
Gel~ from 6 hr labeling ~how that in the ~abQence of ~ subunit FSH-~ i9 retained in the ly~ate, while when the:~ ~BUbUnit i~ pre~ent, the dimer is formed ;and efficie~tly ~ecreted into the medium.
When the cells are pulse~labeled wit~
35S-~cysteine~for~20~min and:chased with unla~eled 2~ ¢y~teine for up~to 12 hr,~result~ for the ~ subunit of~CG
show~the~half-life in lysat~es and appearance of-CG-~ in t~e~medium are~identical;at about 2~hr and almo&t all the secre~ed~ ubunit can~:be recovered:. A lower molecular weigh~ present ~in the:~medium a~parently due to the 25~:~ dif~ereDces; n the extent:of:glycosylation at the 2 APn-:: linked~glyco ylation:sites on CG-~ and is unigue to this ubunit. FSH-~ alone is secreted much les~ efficiently and, a~ does~G-~, di~appear~ from the cell lysates af~er a~out 5 hr; 1 ss than 20~:is recovered in the medium : 30 after 1~ hr.
Simi:larly~:to the ~ subunit~ of:LH and TS~, FSH-alsne is ine ficiently secreted and slowly degraded intracellularly. : Howe~er, the pre~ence of the ~ subunit tabilizes and enhances the secretion of the ~ subunit W093/21947 2 1 1 ~ 3 2 O PCT~US93J04~51 -l5-for FSH. The half-life for diRappearance from the lysates was about 90 min, and 90% was recovered in the medium after l2 hr. This behavior is similar to that shown for TSH, but different from both CG and LH.
I~ i~ apparent from the foregoing results that dif~iculties with ~ecretion are experienced or expression in CHO cells of the genes encoding the ~
: subunits alone; in ome instan~es, this secretion abili~y is mitigated by the presence o~ a vector encQding the ~
~ ~ubunit. However, in general, it appears that CHO cells are not efficient secretors~of the desired ~ subunits or correspondi~g human reproducti~e ho ~ one~
AnQther~difficulty which is apparent from experiments using sulfate label as a source of 35S is ;;l5~ that~for L~ subunit or thP LH heterod.imer, which is k~own to contain ulfated glycosylation in it6 native tate, in~orporation~of label does not take place in CHO
G~ h~s, :~a~ lea t~for LH, and~for:the ~ portion of th~ :heterodimer., which~also contain~:sulfated 2~0~ glyco~ylation~,~HO~;cel~lc sre unable to reproduce the _-~
b~ native::patte~n::for glyco~yla~io~.: Thus, it has been show~ that u~ing,~;~in~place;of ~ysteine, labeled sulfate a~:;a ~ource:o ::ra~ioacti~ity, label does not appear in the~di~er~or~ the ~ hunit of~ L~ produced in CHO cells~

:: 25 ~ ~
: The~:e~pressio~ vectors described aboveincluding :the~ ubunit~ for LH~ CG-~ or FSH-~ either with or without the~a subunit,:and~with the ~:subunit encoded on the same~or different ve~tor wexe tran formed 30~ ~into the:rat~ pituitary cell~ line GH3. After æteady s~tate : :laheling ~y either sulfate (for ~H~ or cys~eine-oriyinated ~for all~:forms) S35,~mature forms of LH, FS~
and hC~ which contained processed oligosaccharide~ were~
~: : :

W~93/21947 2 1 1 8 3 2 0 PCT/U~93/~4051 ~tored in the cells and their release was stimulated by for~kolin. The majority of the ~ ~ubunits of these hormones appeared to be Endo H sensitive and thus re~ide in the ER, but the Endo H resi~tant fraction, which i6 the mature form, was targeted to the regulatory ~ecretory :: pathway with an efficiency that was comparable between : the dimer and the ~ ~ubunit.
Figure 3 shows the result~ obtained from G~3 cells which have been tran~formed with pM2/~ into which ~: 10 the coding ~equence for hH-~ ~ubunit has been inserted into the alternate BamHI site. Lanes 1 and 2 are controls f~om ~H3 ~ell~ which are trans~ormed only ~y pM~/CG~; a i~ evident from the results, the ~ ~ubunit is found mo~tly in the cells themselve~ (C) rather than in : lS ~the ~up#rnate (S? ~n the other hand, lane~ 3 ànd 4 : repre~nt the re ults obtained b~ immunoprecipitating the :~ .
he~rodi~er labeled as de ri~ed above u~i~g cysteine or ul ate~and a~aying the cell medium. A~ ~een from these re~ult~ a large amount of the heterodimer i~ ~ecreted 20~ into~the medium and both the ~ and ~ ~ubunit are able take up }abel rom~5 sulfate.:
n an;additional e ~ eriment, cell~ expres~ing ; :LH were la~eled with~t35S]04 for 16::~rs~to allow accu~ulatio~ of the labeled hormone~ in ~he ~torage :~gran~les. To:~de~crea~e the background of ~onstitutive ~ecretion (i.e., the material not ~ecreted through den~e core granules of the reyulated pathway) following the ab21i~g, the cells were cha ed twice at 2 hr i~tervals :
befo~e timulation (desi~nated I and II in ~igure 4). ~t : 30 the beginning o the:third cha~e (III), 20 ~M of the : ~ secretagogue forskolin (an adenylatecyclase activator) : was added to a duplicate set of wells; a parallel ~et was ~ incubated without ecretagogue. The media (M) and the . W~93/21947 2118 3 2 0 PCT/US93/04~1 cell extracts (L) ~ollowing the third cha~e were precipitated ~y an~ serum and analyzed on SDS-PAGE.
In Figure 4, panel A, lane 1 represen~s the medium at cha~e I. This lane shows that LH~ and ~
subunit~ wexe labeled~by [35S]04. This initial pool is presumably a rapidly secreted, not stored pool. After 4 : ~ ~, hours (II~ and 6 hours (III) of cha~e, the constitutive pool is depleted i~ce no further material is prese~t in the media ~1~a~es 2 and 3 of panel A). Howe~er, there is stil1 a pool of ~H i~. the cell as ~hown by panel A, lane 5 which repre~ents tn~ lysate of cells not treated with : forskoli~. Thi~pool is r~.-lea~ed by the secretagogue :; into the ~edia as shown by 2anel A, lane 4. Lane 6 shows that the intr~cellular pool is depleted following ~orskoli~ treatment~
To demo~strate that radioactive ~ulfate wa~
corporated~i~to N~ ked oligosaccharide~, immunoprecipitated~35S]04 labeled LH was treated with endoglycosida~e~F which is known t:o remove c~mplex N-20~ inked 0ligo~accharides. ~The results of thiæ treatmç~are shown::in~Figure 4, panel B, lane~ I and 2.~ Upon digestion, with~Endo F, the~radioactivity disappeared fo~m~both~a~and~sl~hunits. ~anes 3 and 4 are controls to~how that~t~i~ wa~ not due:to protease activity during :25 ~ incubation.:~ The~e~lanes show the result of Endo F
treatment of LH ~ecreted:into ~he medium after labelIng : ~ with 35S-cy teine. The 35S-cy teine labeled LH subunits collapRe to~a~sin~le band orregponding to the deglycosylated;protein following Endo F dige~tionO
:~ ~ ~ The~e data show that~ LH iæ ~tored in the : ~ ~ GH3 cells~and it ~:release ls:s~imul~ted by 3ecretagogue uch ~torage and:release is not 9een in CH0 cells :~ whethex ~a~eled with S04 or cysteine), (2~ The N-linked :: :

W093~2~947 2 1 i 8 3 2 0 P~T/US93/04~1 .
oligosaccharides of LH are sulfated when produced in GH3 cells.
As~embly of the ~ 3ubunits of these hormones and secretion of the dimers is increased many-fold over that en in CHO cells. The oligosaccharide in the LH
dimer is al~o ~ulfated; howe~er, FSH is normally sialylated in~ ~o,' and thus does not take up label from S04~ ~ :
It has b~en demon~trated that complete 10 ~deglycosylation of human chorionic gonadotropin results in a hormone which retain~ its ability to ~ind to receptor, but :is no longer capable o~ eff~cting the ordinary biological:~re~pon e of the cell on which the receptor i borne. Simila~ effects of ~omplete.
15~ eglyco~ylat;io~are~o~tained with the additional reproductive;~hor~one. LH and FSH.~ Accordingly, alt~ration o the glycosylation::pattern in the ~ subunit may~;:ra ult in:alternative~propertie~. The glycosyl~tion of;the~:hormones an~:~subunits produced b~he method of 2~ he~i~ve~ however;~ more clo~ely:re~emble~ hat o~-the~native~iorm~

The:~honmone~and~oth~r~pharmace~tical of the~
presen~inYe~ion~are formulated ~or~administration u ing 2~ ~method ~generally u~der~tood in~the a~t~ Ty~ical : ; formiulation a~d ~odes of:admi~i tration are descrihed in Mack~Pu~lishing Co., Easton, PA,~ latest~edition.~The~e~formulation~ are typically ~or~ystemic:administrati~:, such as by 30~ :i~jection, but oral~f;ormulations~:or topical ~ormulations may al~o be~employed.
The choice of formul~a~ mode of admini~tration,:and do~age lèYel are ~dependent on the .
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WO93/21947 2 ~ 1 8 3 2 0 PC~/US93/~4051 particular hormone or protein and can be optimized for the appropriate indication u ing generally recognized techniques.

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Claims (8)

Claims

1. An improved method for recombinant production of a human glycoprotein selected from the group consisting of hCG, FSH, LH and TSH, which method comprises culturing animal cells that contain regulated secretory granules, which cells have been modified to contain an expression system capable of expressing a DNA encoding said glycoprotein or the .beta. subunit thereof under conditions wherein said encoding DNA is expressed, and recovering the glycoprotein or .beta. subunit thereof from the culture medium.

2. The method of claim 1 wherein said cells are pituitary cells.

3. The method of claim 2 wherein said pituitary cells are GH3 cells.

4. The method of claim 1 wherein the glycoprotein is LH or FSH.

5. A cell culture capable of secreting a human glycoprotein selected from the group consisting of hCG, FSH, LH and TSH, which cell culture comprises animal cells that contain regulated secretory granules which cells have been modified to contain an expression system capable of expressing a DNA encoding said glycoprotein or the .beta.
subunit thereof.

6. The culture of claim 5 wherein said cells are pituitary cells.

7. The culture of claim 6 wherein said pituitary cells are GH3 cells.

8. The culture of claim 5 wherein the glycoprotein is LH or FSH.